Venting Sustainable Nuclear Fusion...

[Dejected 55]

I know, this seems random... and it is... but randomly I think now and again... there is this big deal made of how we want to create sustainable/containable nuclear fusion reactions for power and whatnot. And the struggle has been going on for decades...

But...

We are literally orbiting a sustained nuclear fusion reaction (the Sun) and we squander the power available to us from it. And I'm not just talking about the fight against solar power technology. I think there ought to be better options IF we tried.

Consider... there is all the hubbub about nuclear fusion. Okay, say tomorrow they figured it out and had a nuclear fusion reaction that sustained and was containable. Then what? What is their plan to convert that energy from the reaction to usable energy for us here on Earth? Really think about that... because it's kind of important. Just about any method by which they would intend to capture the energy from that reaction and use it to produce usable energy for us here... ought to be adaptable to use TODAY for the energy pouring out of our Sun. But we are not doing a good job of that at all.

I get the attraction to mini nuclear fusion reactions in terms of portable power... cool.. not just here but for space exploration and such... but, you know, in the meantime we could be perfecting the capture and use of available energy from a large nearby sustained nuclear fusion reaction so that by the time we figure out how to make smaller/local ones, we have reliable ways to efficiently adapt and use that power.

But... the best we have are the horribly inefficient solar panels that are very expensive. I'm not knocking solar cell development. I'm just saying the astonishing lack of development of alternative ways to use the Sun's energy is holding us back. Maybe solar cells one day can be a lot more efficient and cheaper to produce... but until then... fucking plants are doing a better job of using the Sun's energy than we are.

 

[DarkRange55]

Most fusion paths being explored produce heat that is converted to electricity through a gas (steam, helium, or CO2) turbine.
A few fusion projects plan to capture the energy directly from the moving charged particles, which would indeed be more efficient

The fusion energy of the sun has already been converted to photons with a ~5800K spectrum, but spread out to a mere ~1000W/m2.
To use a gas turbine, we have to concentrate that light to reach high temperatures. This is already done with solar (CST/CSP); it costs more than photovoltaics but the heat energy is easier to store for when the sun isn't shining.

We can't use the other main fusion method of charged particles on earth because the solar wind does not reach the earth, and even in space it is pretty dilute compared to photon.

So what fusion-energy capture method is being proposing to adapt instead?

The sun's energy is available as photons, and yes, these can be used more efficiently. Tandem cells work but are still not yet both reliable and low-cost, and hot-carriers, intermediate-band, and rectennas are all still in the research stage.

They are now merely inefficient (way up from horribly inefficient). and are now the lowest-costway of generating electricity. The only real problem remaining is that the energy is intermittent.

Plants are an order of magnitude (~10x) lessefficient than modern solar panels.

 

[Pluto]

 

[Dejected 55]

Most fusion paths being explored produce heat that is converted to electricity through a gas (steam, helium, or CO2) turbine.
A few fusion projects plan to capture the energy directly from the moving charged particles, which would indeed be more efficient

The fusion energy of the sun has already been converted to photons with a ~5800K spectrum, but spread out to a mere ~1000W/m2.
To use a gas turbine, we have to concentrate that light to reach high temperatures. This is already done with solar (CST/CSP); it costs more than photovoltaics but the heat energy is easier to store for when the sun isn't shining.

We can't use the other main fusion method of charged particles on earth because the solar wind does not reach the earth, and even in space it is pretty dilute compared to photon.

So what fusion-energy capture method is being proposing to adapt instead?

The sun's energy is available as photons, and yes, these can be used more efficiently. Tandem cells work but are still not yet both reliable and low-cost, and hot-carriers, intermediate-band, and rectennas are all still in the research stage.

They are now merely inefficient (way up from horribly inefficient). and are now the lowest-costway of generating electricity. The only real problem remaining is that the energy is intermittent.

Plants are an order of magnitude (~10x) lessefficient than modern solar panels.

Perhaps if they spent less time, money, etc on trying to create fusion here and diverted those efforts into more efficient use of what we already have available?

Meanwhile... Who says we have to only capture the energy from the Sun that reaches us here on Earth? We've sent things to Mars and out of our solar system. We put things in orbit around the Earth routinely. To my thinking, I wonder why we couldn't put something in orbit around the Sun, closer than our orbit but designed to stay in "synchronous" orbit with us so that we always have a line-of-sight to it... use that device closer to the sun to capture energy and transmit it to Earth in a more palatable form. I'm just spitballing, but I can't recall ever hear of anyone trying to put anything in orbit around the Sun.

 

[DarkRange55]

Perhaps if they spent less time, money, etc on trying to create fusion here and diverted those efforts into more efficient use of what we already have available?

Meanwhile... Who says we have to only capture the energy from the Sun that reaches us here on Earth? We've sent things to Mars and out of our solar system. We put things in orbit around the Earth routinely. To my thinking, I wonder why we couldn't put something in orbit around the Sun, closer than our orbit but designed to stay in "synchronous" orbit with us so that we always have a line-of-sight to it... use that device closer to the sun to capture energy and transmit it to Earth in a more palatable form. I'm just spitballing, but I can't recall ever hear of anyone trying to put anything in orbit around the Sun.

"Perhaps if they spent less time, money, etc on trying to create fusion here and diverted those efforts into more efficient use of what we already have available?

Why does it have to be either/or? Fusion R&D is <.01% of global GDP (much less than we spend on soft drinks).

Meanwhile... Who says we have to only capture the energy from the Sun that reaches us here on Earth? We've sent things to Mars and out of our solar system.

We've sent solar-powered explorers to Mars.

We put things in orbit around the Earth routinely. To my thinking, I wonder why we couldn't put something in orbit around the Sun, closer than our orbit but designed to stay in "synchronous" orbit with us so that we always have a line-of-sight to it...

The only stable synch orbits are the Lagrange points, and the meta-stable ones get pretty far from earth.

use that device closer to the sun to capture energy and transmit it to Earth in a more palatable form.

First, we can't yet even get practical amounts of energy from low-earth-orbit back to earth, and that is only a few hundred miles.
Second, enough closer to the sun to increase energy density also increases cooling challenges.

I'm just spitballing, but I can't recall ever hear of anyone trying to put anything in orbit around the Sun."

Outside of the two Voyagers and New Horizons, every craft we have sent out orbits the sun (even LEO and GEO satellites orbit the sun, synchronously with the earth). Probes like Juno orbit the sun before on the way to Jupiter, etc. Also see Parker Solar Probe.

I'm a big fan of solar energy in space - it is the future. But getting it back to earth is hard, even from LEO or GEO (and people are working on it).

 

[Dejected 55]

It just doesn't seem like it... I mean, we launch all kinds of stuff away from us towards the outer solar system or to Mars... but I rarely hear of us launching things towards the Sun. Maybe they do and it just doesn't get talked about.

I don't mind them trying to work on nuclear fusion... but it doesn't seem like they are getting a lot of traction, and meanwhile as I said we already don't use efficiently the energy from our nearby existing nuclear fusion reaction. That tells me that even if we had local small nuclear fusion we would not be using it efficiently... so I'm not sure how much gain we would get out of that unless and until we have more efficient means of using that kind of energy more directly.

I know some of the problem is constantly having to fight the government and other people over working on alternative fuel sources all the time... we hold ourselves back needlessly.

 

[DarkRange55]

It just doesn't seem like it... I mean, we launch all kinds of stuff away from us towards the outer solar system or to Mars... but I rarely hear of us launching things towards the Sun. Maybe they do and it just doesn't get talked about.

I don't mind them trying to work on nuclear fusion... but it doesn't seem like they are getting a lot of traction, and meanwhile as I said we already don't use efficiently the energy from our nearby existing nuclear fusion reaction. That tells me that even if we had local small nuclear fusion we would not be using it efficiently... so I'm not sure how much gain we would get out of that unless and until we have more efficient means of using that kind of energy more directly.

I know some of the problem is constantly having to fight the government and other people over working on alternative fuel sources all the time... we hold ourselves back needlessly.

"It just doesn't seem like it... I mean, we launch all kinds of stuff away from us towards the outer solar system or to Mars... but I rarely hear of us launching things towards the Sun. Maybe they do and it just doesn't get talked about.

Mars is more interesting to look at and easier to land on than Venus (Venus takes similar energy to reach, more energy to land on, and when you land the surface is hot enough to melt lead instead of being able to drive a glorified dune-buggy on).
Jupiter and its moons are far more interesting to look at than Mercury (and Mercury takes similar energy to reach).
The sun is hard to get close to without frying.
And we have sent probes to the inner planets as well as the outer ones.

I don't mind them trying to work on nuclear fusion... but it doesn't seem like they are getting a lot of traction, and meanwhile as I said we already don't use efficiently the energy from our nearby existing nuclear fusion reaction.

The main effort on using sunlight has been to reduce cost, but fairly high efficiencies (approaching 50%) have been reached in the lab.

That tells me that even if we had local small nuclear fusion we would not be using it efficiently...

Most fusion reactors use heat to spin a gas turbine to produce electricity, so fusion just replaces using coal or natural gas as a heat source.

so I'm not sure how much gain we would get out of that unless and until we have more efficient means of using that kind of energy more directly.

Tri-Alpha Energy proposes to capture the energy directly from the moving charged reaction products.

I know some of the problem is constantly having to fight the government and other people over working on alternative fuel sources all the time... we hold ourselves back needlessly."

Most of the challenge is physics and engineering, with some bureaucratic inertia as well.